In wireless sensor networks, adversaries can make use of traffic information to locate the monitored objects, e.g., to hunt endangered animals or kill soldiers. In this paper, the authors first define a hotspot phenomenon that causes an obvious inconsistency in the network traffic pattern due to a large volume of packets originating from a small area. Second, they develop a realistic adversary model, assuming that the adversary can monitor the network traffic in multiple areas, rather than the entire network or only one area. Using this model, they introduce a novel attack called Hotspot-Locating where the adversary uses traffic analysis techniques to locate hotspots.